The present invention relates generally to microbatteries and methods for making same, more specifically to bio-based microbatteries and methods for making same.
Throughout the present specification, all referenced papers and patents are incorporated herein by reference for all purposes.
The present invention provides for materials and methods to battery design by exploiting highly efficient modes of energy transduction and storage found in natural systems, which aims to optimize and maximize system performance in relation to energetic, economic, ergonomic, and environmental aspects. A battery is an assembly of more than one galvanic cell, which converts chemical energy into electrical energy. The first galvanic cell composed of frog muscle was observed by Luigi Galvani in 1762. It was not until 1800 that Allessandro Volta understood and officially documented the electrochemical operation of galvanic cells. By 1859, Geoerges Leclanche developed the first primary (disposable) battery based on the zinc/carbon cell. Surprisingly, these cells are still used world-wide. Development of primary alkaline batteries was a natural progression from the zinc/carbon cell, and by 1866, Gaston Plante produced the secondary (rechargeable) lead/acid battery. In 1899, W. Junger developed the nickel/cadmium battery and in the 20th century, nickel/metal-hydride, lithium, lithium-ion, zinc/air, mercury and silver based batteries emerged and variations thereof to enhance energy densities on a per weight and volume basis. Nowadays, numerous types of battery designs have been commercialized, resulting from an application-based niche, dependent on size, power, energy, convenience, and marketability. Unfortunately, batteries suffer from one or more of the following traits: toxicity, flammablity, explosivity, low energy density, low discharge rate, instability, expensive material use, high fabrication costs, short cycle life, production complexity, and excessive design precautions.
With regards to environmental issues, 85% of the mercury (a highly toxic metal) found in New York""s solid waste in 1996 was attributed to mercury batteries and in 1991, household batteries measured by weight were the second most common source of toxins in U.S. landfills. The need to curb battery toxicity on the environment led to congressional action, such as enacting The Battery Act of 1996 to phase out the use of mercury in batteries and the Implementation of the Mercury-Containing and Rechargeable Battery Management Act of 1997 to provide for the efficient and cost-effective collection, recycling, and disposal of used nickel-cadmium batteries, small sealed lead-acid batteries, and other batteries deemed toxic under the purview of this act. Therefore, the present invention is composed of materials and engineered to significantly reduce device toxicity as opposed to those observed with conventional batteries.
With regards to system size, the present invention is intended to deliver power locally for nanoscopic, mesoscopic, and microscopic devices where conventional technologies falter. For instance, conventional computer circuitries employ transformers for stepping-down currents and voltages in order to prevent power overload of the smaller, local electronic units. The ability to do away with excess transformers will obviously conserve system (i.e., battery) space and weight. Furthermore, due to the environmentally benign material composition of the present invention, disposal of these miniaturized batteries will not require elaborate monitoring or processing of hazardous waste. The present invention with such small dimensions fulfills issues of convenience and allows for the construction of less conspicuous devices.
Accordingly, it is a purpose of the present invention to provide a microbattery that can provide energy densities comparable to conventional batteries, while avoiding the use of hazardous and toxic materials.
It is another object of the present invention to provide an energy source that relies on renewable resources
It is another object of the present invention to provide materials and methods to decrease microbattery processing, production, and disposal costs.
It is another object of the present invention to provide a method for microbattery design with easily tunable currents and voltages.
It is another object of the present invention to provide a method for primary (non-rechargeable/disposable) and secondary (rechargeable) microbattery design.
It is a further object of the present invention to provide methods for making a microbattery that can provide energy densities comparable to conventional batteries, while avoiding the use of hazardous and toxic materials.
These and additional objects of the invention are accomplished by providing a bio-based microbattery and methods of making same.
These and additional objects of the invention are accomplished by immobilizing polymerized vesicles encapsulating electroactive species of differing redox potentials to a conducting substrate. The polymerized vesicle is comprised of chemically and physically stable polymerizable phospholipids or suitable vesicle forming amphiphiles. The vesicle walls may or may not incorporate a liphophilic electron mediator that facilitates the transport of electrons across a vesicle bilayer.
These and additional objects of the invention are further accomplished by providing a galvanic cell comprising an electron acceptor and an electron donor, each being separately encapsulated in polymerized vesicles, wherein the vesicle walls may or may not incorporate an electron mediator and the vesicles are separately immobilized to a conducting substrate and isolated from each other.
These and additional objects of the invention are further accomplished by providing a microbattery comprised of at least one galvanic cell fabricated on or within a conducting substrate.
These and additional objects of the invention are further accomplished by providing a method of immobilizing a polymerized vesicle to a conducting substrate by providing an electroactive polymerized vesicle, a conducting substrate, and a functionalized tether to immobilize the vesicle to the substrate.
These and additional objects are further accomplished by providing an electrode comprising a polymerized vesicle encapsulating an electroactive species, where the vesicle is immobilized by a functionalized tether to a conducting substrate.
These and additional objects are further accomplished by providing a galvanic cell comprising a first electrode as above encapsulating cathodic electroactive activity, a second electrode as above encapsulating anodic electroactive activity, with the first and second electrode being separately immobilized to a conducting substrate, and being physically isolated from each other but having controlled and directed electrical communication between electrodes, wherein a load is connected between the first and said second electrode.
These and additional objects are further accomplished by providing a microbattery comprising at least two galvanic cells as above connected in series or parallel.